Friday, August23, 2019 L-36.com


Marine Weather and Tides
Walhalla, SC

Version 3.4
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7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen

Sunrise 6:55AMSunset 8:10PM Friday August 23, 2019 9:05 AM EDT (13:05 UTC) Moonrise 11:57PMMoonset 1:16PM Illumination 45% Phase: Third Quarter Moon; Moon at 23 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
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7 Day Forecast for Marine Location Near Walhalla, SC
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location: 34.77, -83.07     debug


Area Discussion for - Greenville-Spartanburg, SC
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Fxus62 kgsp 231106
afdgsp
area forecast discussion
national weather service greenville-spartanburg sc
706 am edt Fri aug 23 2019

Synopsis
A cold front will approach the western carolinas today and is
expected to slowly sink south across the forecast area tonight
and Saturday morning. A wedge of cool high pressure is expected
to build into the region behind the front for Sunday and Monday.

Unsettled weather will persist into the middle of next week ahead of
the next cold front, with some drier weather possible by Thursday.

Near term through tonight
As of 650 am: an upper trough axis extends from the eastern
great lakes to the mid-mississippi valley, with an attendant cold
front approaching the ohio river. Embedded within the trough is
a weak shortwave near the southern appalachians, which continues
to regenerate areas of showers storms across the NW half of the
cwfa. The shortwave is becoming less distinct, but the extant
showers have expanded despite model depictions showing a diminishing
trend. Nevertheless the loss of the shortwave should permit the
activity to move out and or fizzle, which is expected to leave a
lull for a few hours before destabilization can reoccur.

The cold front will sag southward thru the day today, but should
remain well north of the fa. The aforementioned upper trough will
make some eastward progress, but the offshore ridge remains the
dominant feature for the southeastern states. Diurnal instability
may be tapped by weak disturbances rounding the ridge and eventually
by dpva downstream of the larger scale trough. Activity is expected
to fire near the blue ridge escarpment more or less as normal for
this time of year, but potentially expanding and clustering as
it propagates east, on account of modest westerly unidirectional
flow. Temps won't be quite as hot as the past couple of days,
but near normal, allowing predictably large sbcape. With the aid
of the shear and 20-25 k of sfc-midlevel delta-theta-e, there will
be potential for some pockets of wind damage if cold-pool driven
clusters do form in the piedmont (and perhaps some isolated wet
microbursts otherwise). Given the former threat, however, spc
has included our eastern nc piedmont zones and vicinity in the
marginal risk.

Tonight, as the tail end of the trough approaches the area, we
will see increasing dynamic lift that could realize any lingering
diurnally generated instability. Confluent flow upstream of
the trough over the great lakes will drive a sfc high in our
direction, which will keep the cold front pushing south in
"backdoor" fashion. Low-level flow will veer to easterly by early
Saturday. The combination will provide added lift, so pops remain
fairly high chance throughout the night. Stratus will settle into
the nc piedmont as well.

Short term Saturday through Sunday night
As of 315 am edt Friday: the evolution of a complex upper blocking
pattern across the great lakes and northeast will afford the western
carolinas and northeast georgia a summertime cold air damming wedge
opportunity over the weekend. Naturally, there are many details
to be ironed out, not the least of which is the passage of the sfc
boundary, which looks like it will drop down as a back-door wedge
front sometime on Saturday. The timing has a big impact on the
fcst. The forecast attempts a compromise between the fast GFS and
slow nam, which results in a trend toward lower precip chances
by Saturday afternoon. As the cad wedge sets up, cooler and more
stable air will filter in from the northeast, which makes for a
tricky temp fcst with high potential for error. Eventually, the
guidance agrees with driving the boundary south of the fcst area
such that Sunday still looks like a cloudy and cool day, probably
with more light rain drizzle production through the morning hours up
against the blue ridge escarpment than our forecast indicates. Temps
will be on the order of 10-15 degrees below normal. The slow decay
of the upper block over the northeast on Monday should allow the
parent high to retain control over our weather even as the air mass
modifies. Eventually, a chunk of the high will likely get pinched
off across the western carolinas Monday night. Precip chances
will slowly taper off to low chance and temps should be only on
the order of 5-10 degrees cooler than normal on Monday afternoon.

Long term Monday through Thursday
As of 405 am edt Friday: the latest guidance out through the medium
range continues to indicate unsettled weather for the first part
of next week. A short wave lifting up the oh valley region on
Monday will support higher precip chances across the mountains
while the weak remnant sfc high stuck between that system and weak
low pressure off the coast of the carolinas will probably result
in a relative lack of precip over the eastern zones. The weak
high will be with us into Tuesday before getting pushed aside. A
large and deep upper low moving into WRN ontario will push another
front toward the area on Tuesday. Some controversy develops as to
when the front will cross the region. The ongoing fcst splits the
middle between the GFS which would dry us out by Wednesday, and the
ecmwf that would keep the precip lingering into Thursday. Temps
will undergo a slow warming trend through the period, but might
not return to normal until the end of the week.

Aviation 11z Friday through Tuesday
At kclt and elsewhere: passing shra this morning at the nc sites
may produce brief vsby restrictions but the downward motion they
bring is likely to keep any low CIGS at bay. These showers are
associated with a weak shortwave which will move east of the
area in the first couple hrs of the period, leaving a lull in
precip activity that is expected to last thru midday. Expect
enhanced coverage of diurnal shra tsra thanks to upper level
disturbances preceding a cold front, which will remain N of the
region today. Generally hit the peak aftn chance period in tempo,
for MVFR vsby in tsra. Tonight, that front will slowly push further
south thru the region and high pressure will encroach from the
northwest, in an incipient cad scenario. Stratus will develop from
n to S as a result in the morning. Leaning in favor of a slightly
slower arrival based on low-level moisture progs and typical model
bias. Included restrictions just before daybreak if at all; the
upstate sites are not likely to see these CIGS until after 12z.

Outlook: shra tsra chances will remain across the area with the
front remaining stalled over the area thru the weekend. Some
morning fog and low stratus will be possible each day, especially
in the mountain valleys. Cold air damming over the weekend will
keep lower CIGS possible.

Confidence table...

11-17z 17-23z 23-05z 05-06z
kclt high 94% high 100% high 100% high 100%
kgsp high 100% high 100% high 100% high 100%
kavl high 94% high 100% low 55% high 100%
khky high 100% high 100% high 100% high 100%
kgmu high 100% high 100% high 100% high 100%
kand high 100% high 100% high 100% high 100%
the percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
CHDS1 - Strom Thurmond Dam, SC 89 mi76 min Calm G 1 79°F

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Clemson, Clemson-Oconee County Airport, SC12 mi72 minN 010.00 miFair75°F73°F94%1017.2 hPa
Pickens County Airport, SC20 mi71 minN 010.00 miFair73°F73°F100%1017.9 hPa

Link to 5 minute data for KCEU

Wind History from CEU (wind in knots)
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Last 24hr5W5W8W564W9
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SW6SW4CalmSW3SE3CalmW4N4N3N3CalmNW3N4CalmCalmCalm
1 day agoCalm3W8W8SW7W8W8W9W74CalmSW3CalmCalmCalmCalmCalmSW3W4SW4W6CalmW6SW5
2 days agoCalmE3NE4W344E7E33CalmCalmCalmCalmCalmCalmSW3W4CalmW3CalmCalmCalmW4Calm

Tide / Current Tables for
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Tide / Current Tables for
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Weather Map and Satellite Images
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GOES Local Image of    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Greenville-Spartanburg, SC (9,2,3,4)
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Ground Weather Radar Station Greer, SC
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weather_mapweather_map weather_map

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Disclaimer:
The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with L-36.com. I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerious of sources and is presented automatically. It is not checked for accuracy either by anyone at L-36.com or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.